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Introduction to Nuclear Astrophysics I Richard H Cyburt “We are made of star stuff” Carl Sagan Nuclear Astrophysics Rich & Diverse Interdisciplinary Field Brings together Experimentalists Observers Modelers Theorists My Plan Part 1: Broad Overview Part 2: Key Concepts & Useful Tools Helpful Literature Burbidge, Burbidge, Fowler & Hoyle (B2FH) Rev. Mod. Phys. 29 (1957) 547. Cameron, Pub. Astron. Soc. Pac. 69 (1957) 201. Cauldrons in the Cosmos, Rolfs & Rodney Principles of Stellar Evolution & Nucleosynthesis, Clayton Nucleosynthesis and Chemical Evolution of Galaxies, Pagel An Introduction to Nuclear Astrophysics, Boyd Nuclear Physics of Stars, Iliadis Nuclear Astrophysics includes Study nuclear processes in stars Origin & Evolution of chemical elements Explosions on/of stars Dense matter of compact stars Determining Important Nuclear Input Modelers can identify key input Masses Cross sections/reaction rates Experimentalists/Theorists produce data Compare to observations What are we made of? See also Asplund, Grevesse & Sauval 2005 and Lodders 2009 Where’s the Nuclear Physics? Did you notice…….? Odd-even staggering of abundances? Larger alpha-nuclei abundance? Broad peak around Fe56? Stable Nuclei only!! For stable nuclei !!! Nuclide Chart Some Nucleosynthesis strays from stability…. While others hug the line of stability Chemical Elements measured by observers do not oftentimes contain isotopic information Where the elements are made Big Bang Nucleosynthesis BBN predictions Obs. comparison Cyburt 2004, 2008 See lectures by T. Kajino & A. Coc for more details Stellar Evolution See lectures by O. Straniero for more details Image from Chandra webpage http://chandra.harvard.edu/edu/formal/stellar_ev/ End Stage of Stellar Evolution White Dwarf & Type Ia Supernova Neutron Star & Core Collapse Supernova See lectures by J. Jose, M. El Eid, W.R. Hix, S. Bishop Heavy Element Nucleosynthesis n-capture Processes Alternating n-capture and beta-decays Rapid or r-process Slow or s-process Time scale ~0.1-1.0 seconds See lecture by K.L. Kratz Time scale ~103-104 years See lecture by M. Busso Are the abundance patterns universal?? Can decompose pattern… Can compare w/ observations r-process enhanced stars Beers & Christlieb 2005; Frebel & Norris 2011 Where does the s-process happen ? there ! in red giants – and it takes several million years ! (or, more correctly, low mass TP-AGB stars) How can we tell ? Analyze light from a red giant: Star contains Technetium (Tc) !!! (heavy element Z=43, T1/2 4 Mio years, Merrill 1952) End of Part I